Abstract

VI. Summary and Conclusions

1.
In feces of pigs collected from Peking markets the common Balantidium, Iodamoeba, Endamoeba polecki, and Trichomonas of the pig have been found. In addition protozoa resembling E. coli, E. dysenteriae, E. nana, and Chilomastix mesnili have been found.

2.
The differences between the endamoebae of naturally infected pigs are discussed and it is concluded that E. polecki Prowazek 1912 should be the name applied to the amoeba forming mononucleate cysts and that E. dysenteriae Councilman and Lafleur 1891 is the amoeba in the pig which forms four-nucleate cysts.

3.
E. debliecki Nieschulz 1923 is regarded as a synonym of E. polecki and E. suis Hartmann 1912 is probably the amoeba which forms four nucleate cysts discussed in this paper.

4.
Negative pigs fed cysts of the intestinal protozoa of man have become infected with E. dysenteriae, E. coli, E. nana and Chilomastix mesnili of man and the infections have persisted for a period of six weeks.

5.
The finding of E. dysenteriae in naturally infected pigs and the successful experimental infection of pigs with E. dysenteriae of man indicate that the pig may serve as a reservoir host of this amoeba though it may be only a temporary host since the infection may be lost spontaneously after a period of about six weeks.

6.
The dysentery amoeba (a) of the naturally infected pig, (b) of man experimentally established in the pig and (c) of the monkey experimentally established in the pig have all been successfully cultured in the egg-serum medium and have been experimentally transferred to kittens which have developed the same pathology found in kittens infected directly with the dysentery amoeba from man.